Valve-operating structure for motor cycles



A.ROSSI April 12, 1927.

VALVE OPERATING STRUCTURE FOR MOTOR CYCLES Filed Sept. 8, 1925 INVENTOR Patented Apr. 12, 1927.

, UNITED STATES ANGELO ROSSI, OF SANTA ROSA, CALIFORNIA.

VALVE OPERATING STRUCTURE FOR MOTOR CYCLES.

Application filed September This invention relates to improvements in motorcycle construction and particularly to the valve tappet actuating means. In motorcycles of at least one certain standard make, the rollers of the tappet actuating rocker arms operate on a single cam. This arrangement makes it impossible to give each tappet the proper dwell and raise of opening it should have, since conditions which are correct for the intake valve are not suitable for the exhaust valve and vice versa. 7

The results are that the engine cannot function to the best of its ability and only mediocre efficiency is obtained.

The principal object of my invention therefore is to eliminate the above defects in operation by arranging an individual cam for each rocker arm, so that the cams can be designed to give such lift and dwell to the tappets as has been determined to be most suited for the purpose by the best engineering practice.

At the same time the structure is such that no changes have to be made to the standard engine assembly in order to install my structure therein.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a fragmentary end outline of the gear box of a motorcycle and certain of the gearing therein, showing my tappet operating mechanism as arranged for one cylinder.

Fig. 2 is a side view of the cam, gear and rocker arm unit detached.

Fig. 3 is an end view of the same.

Referring now more particularly to the characters of reference marked thereon, the

' numeral 1 denotes the gear case of the motorcycle in which as standard equipment are mounted a pinion 2 on the crankshaft 3, said piniondriving a gear 4 which in turn drives a gear 5 the same size as said gear 4.

The gears 4 and 5 which I retain are used in connection with the valve operating mecl'ianism of the two cylinders of the motorcycle, if the engine is of course a two 8, 1925. Serial no. 55,183.

cylinder engine. Since such .mechanisms are identical I only show and describe one of the same.

Such mechanism for the valves of each cylinder comprises apair of cams (3 and 7 for the intakeand exhaust valvesrespectively, which cams are permanently connected to a gear 5 so as to turn as a unit on the gear shaft 8. These cams are set at such positions relative to each other that the opening of the different valves will be properly timed with respect to each other, and they are so designed that the valves will have the proper amount and dwell of lift.

Independently turnable on a stub shaft 9 mounted in the case 1 above the gear 5 are oppositely disposed rocker arms 10 and 11 for the cams 6 and 7 respectively.

The lower ends of the rocker arms carry rollers 12 and are offset from each other transversely so that said rollers will bear on the respective cam faces without interference. The opposite upper ends of the rocker arms havepads 13 disposed in longitudinal. alinement to aline with the lower ends of the corresponding valve tappets 1 L which pro ject into the case 1. In installing my improved structure it is only necessary to remove the original gears & and 5 and their cams, together with the rocker arms, and replace such parts with the corresponding members constructed according to my invention.

As previously stated, these improved parts fit in place in the gear case without necessitating any changes being made to the case or to any other members of the engine assembly. I

From the foregoing description it will. be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

lVhile this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. An operating structure for an adjacent pair of transversely alined motorcycle valvetappets, comprising a pair of opposed rocker arms pivoted independently of each other, the upper and opposite ends of said arms till being in common transverse alinenient to bear against the tappets, rollers pro eet1ng from the same side of the arms at their lower opposed ends and arranged so as to be laterally oll'set, and independent cams to engage the rollers mounted on a common axis, said cams being of different diameters and the larger can) being the farthest from the plane of the arms whereby to enable the rollers being of the same size While prevent ing the apex of one 0am from striking the arm of the other roller at any period in its rotation.

2. An operating structure or an adjacent pair of transversely alined motorcycle valvetappets, comprising a pair of opposed rocker arms pivoted independently of each other, the upper and opposite ends of said arms being in common transverse alinement to bear against the tappets, rollers projecting from the same side of the arms at their lower opposed ends and arranged so as to be laterally otl'set, and independent came to engage the rollers mounted on a common axis, the distance from the axis of the cams to the lower end of one arm being not less than the greatest radius ol. the can: of the other man.

111 testimony whereof afllx my signature.

ANGELO ROSS]. 

